2lU Prof. R. Clausius on the Determination of the 



with (4) make the following transformation, 



lf d 2 v lf d (dr\ d ( lf dr\ d ( v ,dr\ 



and, besides, put everywhere 





Then we get 



Just so we obtain for the negative electricity —7i'ds f } flowing 

 with the velocity —c\, 



The sum of these two expressions represents the # compo- 

 nent of the force which the entire current-element ds f must, 

 according to Weber's fundamental law, exert upon the unit of 

 electricity. If this is denoted by leads' , then we have 



This expression of r 2 can, like the above expression of r 1; be 

 brought into such a form as to appear as the sum of £ and 

 some superadded terms. For that purpose we will divide the 

 preceding^ equation by k, then carry out on the right-hand 



side the suggested multiplication by - — 3—, and at the same 



time resolve some of the terms. Above the resulting terms 

 we will place numbers, in order to be able afterwards to desig- 

 nate them simply by the numbers: — 



1 2 3, 



&_ .,x — a/ ^r B?- x — x' jj/yBgN i'(cf — cf\) x—x' fir X 

 k~ l r 3 B*d/ r 1 d*v3«7 2 r 3 \&J) 



- + *J^ *[*(*-, J*} 



4 5 



x — x' "d 2 r 



